Here's a good one...

D

Daniel Rudy

When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH'
ex7-2.c:110: `year' undeclared here (not in a function)
ex7-2.c:110: initializer element is not constant
ex7-2.c:110: warning: data definition has no type or storage class
ex7-2.c:111: warning: data definition has no type or storage class
ex7-2.c:112: `day' undeclared here (not in a function)
ex7-2.c:112: warning: data definition has no type or storage class
ex7-2.c:116: syntax error before `while'
strata:/home/dcrudy/c/exercise 1132 $$$ ->

For the life of me, I cannot seem to figure out why some of these are
errors. The compiler that I'm using is gcc 2.95.3. The ones that are
really puzzling is the errors on 110 and 112. It says that 'year' is
not in a function. It most definatly *IS* in a function, and it is
being used in that function. It also says these errors are at the top
level. What the hell? I followed the example in the book, so I'm at a
loss as to what the problem is.

Here's the program:

strata:/home/dcrudy/c/exercise 1135 $$$ ->cat -n ex7-2.c
1 /*
2
3 Programming Exercise 7-2 Page 111
4
5 Write a program to perform date arithmetic such as how many
6 days there are between 6/6/90 and 4/3/92.
7
8 */
9
10 #include <stdio.h>
11 #include <string.h>
12
13
14 const int YEAR=365; /* Days in a year */
15 int LEAP=366; /* Days in a leap year */
16
17
18 char line[100]; /* user data input line */
19 int sday; /* day start input */
20 int smonth; /* month start input */
21 int syear; /* year start input */
22 int eday; /* day end input */
23 int emonth; /* month end input */
24 int eyear; /* year end input */
25 int jstart; /* julian start date */
26 int jend; /* julian end data */
27 int result; /* calculation result */
28
29
30 /* Checks to see if the given year is a leap year */
31 int check_leap(int year)
32 {
33 /* We need to check on 3 cases for this.
34 1. Every year divisible by 4 is a leap year.
35 2. But, if the year is divisible by 100, then it
36 is not a leap year.
37 3. Unless the year is also divisible by 400, then
38 it is still a leap year.
39 */
40
41 const int LEAPYEAR = 4; /* leap year modulus */
42 const int LEAPNONE = 100; /* leap 1 century modulus */
43 const int LEAPCENT = 400; /* leap 4 century modulus */
44 int result1;
45 int result2;
46 int result3;
47
48 /* Check if the year is > 399. Used for the every 400
49 years rule. */
50 if (year > 399)
51 {
52 result1 = year % LEAPYEAR;
53 result2 = year % LEAPNONE;
54 result3 = year % LEAPCENT;
55 }
56 else if (year > 99)
57 {
58 result1 = year % LEAPYEAR;
59 result2 = year % LEAPNONE;
60 result3 = 1;
61 }
62 else
63 {
64 result1 = year % LEAPYEAR;
65 result2 = 1;
66 result3 = 1;
67 }
68
69 /* Check if the given year is divisible by 4. If so, then
70 we need to check if the year is divisible by 100. If so,
71 then we also need to check if the year is divisible by 400.
72 If so, then it is a leap year. If not, then we do not have
73 a leap year. */
74 if (result1 == 0)
75 {
76 if (result2 == 0)
77 {
78 if (result3 == 0)
79 {
80 return(1);
81 }
82 else
83 {
84 return(0);
85 }
86 }
87 else
88 {
89 return(1);
90 }
91 }
92 else
93 {
94 return(0);
95 }
96 }
97
98
99 /* Takes the given date and converts it to the julian format */
100 int conv_julian(int month, int day, int year)
101 {
102 const int array MONTHLENGTH[12] =
{31,28,31,30,31,30,31,31,30,31,30,31};
103 const int array MONTHLEAPLENGTH[12] =
{31,29,31,30,31,30,31,31,30,31,30,31};
104
105 int leapflag; /* set to true if the given date is a
leap year. */
106 int count; /* counter for the month */
107 int daycount; /* day counter */
108
109 /* Init our variables */
110 leapflag = check_leap(year);
111 count = 0;
112 daycount = day;
113
114 /* Loop to add up the days of the months, minus
115 the current month. */
116 while (count < month - 1)
117 {
118 if (leapflag)
119 {
120 daycont = daycount + MONTHLEAPLENGTH[count];
121 }
122 else
123 {
124 daycont = daycount + MONTHLENGTH[count];
125 }
126 ++count;
127 }
128
129 /* Return our result */
130 return(daycount);
131 }
132
133
134
135 int main()
136 {
137 /* Get User Input */
138 printf("Input begining and ending dates (month day year) ");
139 fgets(line, sizeof(line), stdin);
140 sscanf(line, "%d %d %d %d %d %d", &smonth, &sday, &syear,
141 &emonth, &eday, &eyear);
142
143 /* convert given dates to julian format */
144 jstart = conv_julian(smonth, sday, syear);
145 jend = conv_julain(emonth, eday, eyear);
146
147 /* We have a couple of special cases to deal with */
148
149 /* Check for same year */
150 if (syear == eyear)
151 {
152 result = jend - jstart;
153 }
154 else
155 {
156 int leap; /* flag for if the begining year is a
leap */
157
158 leap = check_leap(syear);
159 if (leap)
160 {
161 result = (LEAP - jstart) + jend;
162 }
163 else
164 {
165 result = (YEAR - jstart) + jend;
166 }
167 if (syear + 1 > eyear)
168 {
169 int count; /* generic counter */
170
171 count = syear + 1;
172 while (count < eyear)
173 {
174 leap = check_leap(count);
175 if (leap)
176 {
177 result += LEAP;
178 }
179 else
180 {
181 result += YEAR;
182 }
183 ++count;
184 }
185
186 }
187 }
188
189 /* printout result */
190 printf("Difference in days is %d.\n", result);
191
192 /* return to operating system */
193 return(0);
194 }
195
196
strata:/home/dcrudy/c/exercise 1136 $$$ ->
 
J

Jirka Klaue

Daniel said:
When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH' ....
102 const int array MONTHLENGTH[12] =
Click to expand...
^^^^^

What is this 'array'?

const int MONTHLENGTH[12] =

Jirka
 
C

CBFalconer

Daniel said:
When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH'
ex7-2.c:110: `year' undeclared here (not in a function)
ex7-2.c:110: initializer element is not constant
ex7-2.c:110: warning: data definition has no type or storage class
ex7-2.c:111: warning: data definition has no type or storage class
ex7-2.c:112: `day' undeclared here (not in a function)
ex7-2.c:112: warning: data definition has no type or storage class
ex7-2.c:116: syntax error before `while'
strata:/home/dcrudy/c/exercise 1132 $$$ ->

For the life of me, I cannot seem to figure out why some of these are
errors. The compiler that I'm using is gcc 2.95.3. The ones that are
really puzzling is the errors on 110 and 112. It says that 'year' is
Click to expand...
.... snip ...

Fix the first error listed, or maybe the first two. Then try
again. Subsequent errors are often bogus, because the source is
syntactic nonsense until the earlier errors are fixed.

If you can't see what your error is, go back and read your C book
again.
 
K

Karthik

Daniel said:
When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH'
ex7-2.c:110: `year' undeclared here (not in a function)
ex7-2.c:110: initializer element is not constant
ex7-2.c:110: warning: data definition has no type or storage class
ex7-2.c:111: warning: data definition has no type or storage class
ex7-2.c:112: `day' undeclared here (not in a function)
ex7-2.c:112: warning: data definition has no type or storage class
ex7-2.c:116: syntax error before `while'
strata:/home/dcrudy/c/exercise 1132 $$$ ->

For the life of me, I cannot seem to figure out why some of these are
errors. The compiler that I'm using is gcc 2.95.3. The ones that are
really puzzling is the errors on 110 and 112. It says that 'year' is
not in a function. It most definatly *IS* in a function, and it is
being used in that function. It also says these errors are at the top
level. What the hell? I followed the example in the book, so I'm at a
loss as to what the problem is.

Here's the program:

strata:/home/dcrudy/c/exercise 1135 $$$ ->cat -n ex7-2.c
Click to expand...

My two cents - When pasting the code, please ignore the line numbers
and paste it as such - a compilable fragment so that people can help better.
 
D

Darrell Grainger

When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
Click to expand...

Find and fix the error above line 102. there is most likely a missing
semicolon or a misplaced comma. Once you have fixed this error re-compile
your program.

I used to have an example I'd show students. You compile it and it
generates 57 errors. You fix the first error and re-compile it. It has
zero errors. The one error at the beginning threw off the parsing of
everything from that point onward.

For beginners, always fix the first error then re-compile. After a while
you will be able to spot the real errors from the ghost errors. Until
then, fix them one at a time.
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH'
ex7-2.c:110: `year' undeclared here (not in a function)
ex7-2.c:110: initializer element is not constant
ex7-2.c:110: warning: data definition has no type or storage class
ex7-2.c:111: warning: data definition has no type or storage class
ex7-2.c:112: `day' undeclared here (not in a function)
ex7-2.c:112: warning: data definition has no type or storage class
ex7-2.c:116: syntax error before `while'
strata:/home/dcrudy/c/exercise 1132 $$$ ->

For the life of me, I cannot seem to figure out why some of these are
errors. The compiler that I'm using is gcc 2.95.3. The ones that are
really puzzling is the errors on 110 and 112. It says that 'year' is
not in a function. It most definatly *IS* in a function, and it is
being used in that function. It also says these errors are at the top
level. What the hell? I followed the example in the book, so I'm at a
loss as to what the problem is.

Here's the program:

strata:/home/dcrudy/c/exercise 1135 $$$ ->cat -n ex7-2.c
1 /*
2
3 Programming Exercise 7-2 Page 111
4
5 Write a program to perform date arithmetic such as how many
6 days there are between 6/6/90 and 4/3/92.
7
8 */
9
10 #include <stdio.h>
11 #include <string.h>
12
13
14 const int YEAR=365; /* Days in a year */
15 int LEAP=366; /* Days in a leap year */
16
17
18 char line[100]; /* user data input line */
19 int sday; /* day start input */
20 int smonth; /* month start input */
21 int syear; /* year start input */
22 int eday; /* day end input */
23 int emonth; /* month end input */
24 int eyear; /* year end input */
25 int jstart; /* julian start date */
26 int jend; /* julian end data */
27 int result; /* calculation result */
28
29
30 /* Checks to see if the given year is a leap year */
31 int check_leap(int year)
32 {
33 /* We need to check on 3 cases for this.
34 1. Every year divisible by 4 is a leap year.
35 2. But, if the year is divisible by 100, then it
36 is not a leap year.
37 3. Unless the year is also divisible by 400, then
38 it is still a leap year.
39 */
40
41 const int LEAPYEAR = 4; /* leap year modulus */
42 const int LEAPNONE = 100; /* leap 1 century modulus */
43 const int LEAPCENT = 400; /* leap 4 century modulus */
44 int result1;
45 int result2;
46 int result3;
47
48 /* Check if the year is > 399. Used for the every 400
49 years rule. */
50 if (year > 399)
51 {
52 result1 = year % LEAPYEAR;
53 result2 = year % LEAPNONE;
54 result3 = year % LEAPCENT;
55 }
56 else if (year > 99)
57 {
58 result1 = year % LEAPYEAR;
59 result2 = year % LEAPNONE;
60 result3 = 1;
61 }
62 else
63 {
64 result1 = year % LEAPYEAR;
65 result2 = 1;
66 result3 = 1;
67 }
68
69 /* Check if the given year is divisible by 4. If so, then
70 we need to check if the year is divisible by 100. If so,
71 then we also need to check if the year is divisible by 400.
72 If so, then it is a leap year. If not, then we do not have
73 a leap year. */
74 if (result1 == 0)
75 {
76 if (result2 == 0)
77 {
78 if (result3 == 0)
79 {
80 return(1);
81 }
82 else
83 {
84 return(0);
85 }
86 }
87 else
88 {
89 return(1);
90 }
91 }
92 else
93 {
94 return(0);
95 }
96 }
97
98
99 /* Takes the given date and converts it to the julian format */
100 int conv_julian(int month, int day, int year)
101 {
102 const int array MONTHLENGTH[12] =
{31,28,31,30,31,30,31,31,30,31,30,31};
Click to expand...

The error is right here. Same error on line 103 as well. Tell me what the
different elements of this line are:

const? modifier
int? data type
array? ...
MONTHLENGTH? ...
[12]? ...
103 const int array MONTHLEAPLENGTH[12] =
{31,29,31,30,31,30,31,31,30,31,30,31};
104
105 int leapflag; /* set to true if the given date is a
leap year. */
106 int count; /* counter for the month */
107 int daycount; /* day counter */
108
109 /* Init our variables */
110 leapflag = check_leap(year);
111 count = 0;
112 daycount = day;
113
114 /* Loop to add up the days of the months, minus
115 the current month. */
116 while (count < month - 1)
117 {
118 if (leapflag)
119 {
120 daycont = daycount + MONTHLEAPLENGTH[count];
121 }
122 else
123 {
124 daycont = daycount + MONTHLENGTH[count];
125 }
126 ++count;
127 }
128
129 /* Return our result */
130 return(daycount);
131 }
132
133
134
135 int main()
136 {
137 /* Get User Input */
138 printf("Input begining and ending dates (month day year) ");
139 fgets(line, sizeof(line), stdin);
140 sscanf(line, "%d %d %d %d %d %d", &smonth, &sday, &syear,
141 &emonth, &eday, &eyear);
142
143 /* convert given dates to julian format */
144 jstart = conv_julian(smonth, sday, syear);
145 jend = conv_julain(emonth, eday, eyear);
146
147 /* We have a couple of special cases to deal with */
148
149 /* Check for same year */
150 if (syear == eyear)
151 {
152 result = jend - jstart;
153 }
154 else
155 {
156 int leap; /* flag for if the begining year is a
leap */
157
158 leap = check_leap(syear);
159 if (leap)
160 {
161 result = (LEAP - jstart) + jend;
162 }
163 else
164 {
165 result = (YEAR - jstart) + jend;
166 }
167 if (syear + 1 > eyear)
168 {
169 int count; /* generic counter */
170
171 count = syear + 1;
172 while (count < eyear)
173 {
174 leap = check_leap(count);
175 if (leap)
176 {
177 result += LEAP;
178 }
179 else
180 {
181 result += YEAR;
182 }
183 ++count;
184 }
185
186 }
187 }
188
189 /* printout result */
190 printf("Difference in days is %d.\n", result);
191
192 /* return to operating system */
193 return(0);
194 }
195
196
strata:/home/dcrudy/c/exercise 1136 $$$ ->


--
Daniel Rudy

Email address has been encoded to reduce spam.
Remove all numbers, then remove invalid, email, no, and spam to reply.
Click to expand...
 
D

Dave Vandervies

My two cents - When pasting the code, please ignore the line numbers
and paste it as such - a compilable fragment so that people can help better.
Click to expand...

Two more cents:
When you post compiler errors that refer to a line number, instead
of giving line numbers in your post (which makes it hard to
copy-paste-compile), put a comment like:

/*Line 102 - this is what the compiler is complaining about*/

in the appropriate place. That way we (the people who are willing and
potentially able to help) can either copy-paste-compile and see what our
compilers have to say, or just desk-check it without counting lines to
see if we can find the error that way.


dave
 
M

Mike Wahler

"Daniel Rudy"
<i0n1v2a3l4i5d6d7c8r9u0d1y2e3m4a5i6l7@n0o1p2a3c4b5e6l7l8s9p0a1m2.3n4e5t6>
wrote in message
[snip]
99 /* Takes the given date and converts it to the julian format */
100 int conv_julian(int month, int day, int year)
101 {
102 const int array MONTHLENGTH[12] =
Click to expand...


Sing to the tune of the 'Oscar Meyer' jingle:

My array has a first name ...
My array has a second name ...

-Mike
 
D

Dan Pop

It's a trivial one, actually.

When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH'
ex7-2.c:110: `year' undeclared here (not in a function)
ex7-2.c:110: initializer element is not constant
ex7-2.c:110: warning: data definition has no type or storage class
ex7-2.c:111: warning: data definition has no type or storage class
ex7-2.c:112: `day' undeclared here (not in a function)
ex7-2.c:112: warning: data definition has no type or storage class
ex7-2.c:116: syntax error before `while'
strata:/home/dcrudy/c/exercise 1132 $$$ ->

For the life of me, I cannot seem to figure out why some of these are
errors. The compiler that I'm using is gcc 2.95.3. The ones that are
really puzzling is the errors on 110 and 112. It says that 'year' is
not in a function. It most definatly *IS* in a function, and it is
being used in that function. It also says these errors are at the top
level. What the hell? I followed the example in the book, so I'm at a
loss as to what the problem is.
Click to expand...

Always look at earliest (in terms of line numbers) diagnostic reported
by the compiler and ignore the rest. Fix it, recompile and follow
the same strategy if there are still diagnostics.

In your case, it is line 102 (or something right before it) that needs
your attention, so let's have a look:
99 /* Takes the given date and converts it to the julian format */
100 int conv_julian(int month, int day, int year)
101 {
102 const int array MONTHLENGTH[12] =
{31,28,31,30,31,30,31,31,30,31,30,31};
Click to expand...

Barring some preprocessor magic, "array" is a syntax error in the
definition of MONTHLENGTH. Remove it and recompile.

So, the compiler pointed you *exactly* at the right place, yet you failed
to find it...

Dan
 
D

Dan Pop

In said:
My two cents - When pasting the code, please ignore the line numbers
and paste it as such - a compilable fragment so that people can help better.
Click to expand...

Bogus advice. When posting compiler diagnostics that include line
numbers, make sure that the posted code also includes line numbers.

The OP got this bit perfectly right. Line numbers are a nuisance when
the code compiles cleanly and the problem is caused by the program's run
time behaviour. It is then that other people might want to compile the
code, but it makes no sense to try to compile a piece of code that you
know in advance that it is syntactically incorrect and also have the
compiler diagnostics included in the post.

Dan
 
D

Daniel Rudy

And somewhere around the time of 06/08/2004 09:05, the world stopped and
listened as Dan Pop contributed the following to humanity:
It's a trivial one, actually.



When I try to compile the program below, I get these errors:

strata:/home/dcrudy/c/exercise 1131 $$$ ->cc -g -oex7-2 ex7-2.c
ex7-2.c: In function `conv_julian':
ex7-2.c:102: syntax error before `MONTHLENGTH'
ex7-2.c: At top level:
ex7-2.c:103: syntax error before `MONTHLEAPLENGTH'
ex7-2.c:110: `year' undeclared here (not in a function)
ex7-2.c:110: initializer element is not constant
ex7-2.c:110: warning: data definition has no type or storage class
ex7-2.c:111: warning: data definition has no type or storage class
ex7-2.c:112: `day' undeclared here (not in a function)
ex7-2.c:112: warning: data definition has no type or storage class
ex7-2.c:116: syntax error before `while'
strata:/home/dcrudy/c/exercise 1132 $$$ ->

For the life of me, I cannot seem to figure out why some of these are
errors. The compiler that I'm using is gcc 2.95.3. The ones that are
really puzzling is the errors on 110 and 112. It says that 'year' is
not in a function. It most definatly *IS* in a function, and it is
being used in that function. It also says these errors are at the top
level. What the hell? I followed the example in the book, so I'm at a
loss as to what the problem is.
Click to expand...


Always look at earliest (in terms of line numbers) diagnostic reported
by the compiler and ignore the rest. Fix it, recompile and follow
the same strategy if there are still diagnostics.

In your case, it is line 102 (or something right before it) that needs
your attention, so let's have a look:

99 /* Takes the given date and converts it to the julian format */
100 int conv_julian(int month, int day, int year)
101 {
102 const int array MONTHLENGTH[12] =
{31,28,31,30,31,30,31,31,30,31,30,31};
Click to expand...


Barring some preprocessor magic, "array" is a syntax error in the
definition of MONTHLENGTH. Remove it and recompile.

So, the compiler pointed you *exactly* at the right place, yet you failed
to find it...

Dan
Click to expand...

To all who replied, thanks. The book does not give any examples on how
to declare an array constant...Come to think of it, an array variable
doesn't use array either. You know, that was a Pascal construct and I
didn't realize it until it was pointed out.
 
M

Mike Wahler

"Daniel Rudy"
To all who replied, thanks. The book
Click to expand...

May I ask which book you're reading?
does not give any examples on how
to declare an array constant...
Click to expand...

You declare an object as constant with the 'const'
keyword, as you did. This doesn't matter if the
object is an array or some other type.
Come to think of it, an array variable
doesn't use array either.
Click to expand...

No it doesn't *use* an array, it *is* an array.
You know, that was a Pascal construct and I
didn't realize it until it was pointed out.
Click to expand...

Perhaps you need a better book. C syntax does not
designate an array with a keyword such as 'array'.
That word can be used for an identifier for any
type of object, array or otherwise. It's the
pair of brackets ( [] ) after an identifier name
that designates an array type.

-Mike
 
K

Keith Thompson

Mike Wahler said:
"Daniel Rudy"
<i0n1v2a3l4i5d6d7c8r9u0d1y2e3m4a5i6l7@n0o1p2a3c4b5e6l7l8s9p0a1m2.3n4e5t6>
wrote in message news:[email protected]... [...]
Come to think of it, an array variable
doesn't use array either.
Click to expand...

No it doesn't *use* an array, it *is* an array.
Click to expand...

He meant that it doesn't use the word "array".

To a C novice who's accustomed to Pascal, it's fairly easy to miss the
fact that C doesn't have an "array" keyword. And since the error
message didn't say "C doesn't have an 'array' keyword", it's
understandable that a novice might be confused.

(Now that the OP understands that, perhaps we can refrain from a
lengthy debate about what is and isn't obvious.)
 
K

Keith Thompson

Always look at earliest (in terms of line numbers) diagnostic reported
by the compiler and ignore the rest. Fix it, recompile and follow
the same strategy if there are still diagnostics.
Click to expand...

That's good advice for beginners, and it certainly applies to the OP's
code.

The more advanced version is:

Always look at the earliest diagnostic reported by the compiler.
Anything following a syntax error can probably be ignored; typical C
compilers don't recover well from syntax errors. But semantic errors
(type mismatches, etc.) typically don't cause the same kind of
cascades that syntax errors do.

The very first error message you see is almost certainly meaningful.

Error messages up to and including the first reported syntax error are
likely to be meaningful, but don't spend too much time on them; if you
can't figure out the error, fix the first one (or the first N) and
recompile.

Error messages following a syntax error are likely to be meaningless
cascade errors.

Errors involving typedef names often behave like syntax errors (since
a typedef name is effectively a keyword in most contexts).

Having said all that, fixing each error one at a time and recompiling
for each fix isn't an unreasonable approach. (I usually try to fix as
many errors as I can, because I typically build large software
packages with multiple levels of auto-configuration and Makefiles;
re-running a single compilation isn't always practical, and the entire
build can take hours. A novice isn't likely to be in that situation.)
 
D

Daniel Rudy

And somewhere around the time of 06/08/2004 11:02, the world stopped and
listened as Mike Wahler contributed the following to humanity:
May I ask which book you're reading?
Click to expand...

Practical C Programming published by O'Riely & Associates.
You declare an object as constant with the 'const'
keyword, as you did. This doesn't matter if the
object is an array or some other type.





No it doesn't *use* an array, it *is* an array.
Click to expand...

I meant 'array' as in a keyword. The pascal equivilent would be

Type
MonthArray = Array[1..12] of Integer;

Const
monthyear: MonthArray = (31,28,31,30,31,30,31,31,30,31,30,31);

But, I forgot that C doesn't have the array qualifier like Pascal does.
You know, that was a Pascal construct and I
didn't realize it until it was pointed out.
Click to expand...


Perhaps you need a better book. C syntax does not
designate an array with a keyword such as 'array'.
That word can be used for an identifier for any
type of object, array or otherwise. It's the
pair of brackets ( [] ) after an identifier name
that designates an array type.

-Mike
Click to expand...

The book did have it correctly. I just didn't read it right.
 
D

Dan Pop

You declare an object as constant with the 'const'
keyword, as you did. This doesn't matter if the
object is an array or some other type.
Click to expand...

This is misleading, as well the keyword "const" itself.
You declare an object as constant with a compound literal (in C99 only).
C89 does not support constant objects at all, "const" merely makes them
read only (which is not the same as constant).

Dan
 
D

Dan Pop

In said:
Having said all that, fixing each error one at a time and recompiling
for each fix isn't an unreasonable approach. (I usually try to fix as
many errors as I can, because I typically build large software
packages with multiple levels of auto-configuration and Makefiles;
re-running a single compilation isn't always practical, and the entire
build can take hours.
Click to expand...

In my naivety, I thought that the whole point of using makefiles is that
work already successfully done is not redone unnecessarily. So,
restarting the build procedure should have precious little overhead and
the recompilation of the offending source file should start in a matter
of seconds (for a large package and practically instantly for a reasonably
sized project).

To accelerate things even further, after editing a file that doesn't
compile, I merely recompile it, by executing the same command used by
the build procedure (it's on my screen, so I can copy and paste it).
When it compiles cleanly, I can restart the building procedure of the
package.

Dan
 
M

Mike Wahler

Dan Pop said:
In <[email protected]> "Mike Wahler"

This is misleading,
Click to expand...

Yes, I see now it could be.
as well the keyword "const" itself.
You declare an object as constant with a compound literal (in C99 only).
C89 does not support constant objects at all, "const" merely makes them
read only (which is not the same as constant).
Click to expand...

Right. My explanation was sloppy. I suppose the
name of the 'const' keyword is unfortunate.

Thanks for the correction.

-Mike
 
K

Keith Thompson

In my naivety, I thought that the whole point of using makefiles is that
work already successfully done is not redone unnecessarily. So,
restarting the build procedure should have precious little overhead and
the recompilation of the offending source file should start in a matter
of seconds (for a large package and practically instantly for a reasonably
sized project).

To accelerate things even further, after editing a file that doesn't
compile, I merely recompile it, by executing the same command used by
the build procedure (it's on my screen, so I can copy and paste it).
When it compiles cleanly, I can restart the building procedure of the
package.
Click to expand...

Ideally, yes. But if the invocation of make is buried under layers of
customized build tools, which require the sources to be inside nested
gzipped tarballs, it's sometimes easier to restart the build and let
it run while I'm off doing something else. Since the software is
pre-packaged and tested before it gets to me, I seldom run into
compilation failures anyway.

If you want to say that this is a flawed method for building software,
I won't argue with you -- both because you're right and because it's
off-topic.
 
D

Dan Pop

In said:
Ideally, yes.
Click to expand...

Practically, too, as I'm doing it quite often when dealing with huge
packages that have to be moved from one compiler to another.
But if the invocation of make is buried under layers of
customized build tools, which require the sources to be inside nested
gzipped tarballs, it's sometimes easier to restart the build and let
it run while I'm off doing something else.
Click to expand...

I have never encountered *any* difficulty in copying and pasting the
last compilation command (the one that failed). That is, after switching
to an environment supporting copy and paste :)
Since the software is
pre-packaged and tested before it gets to me, I seldom run into
compilation failures anyway.
Click to expand...

You're a lucky guy. I only get to work on such things after someone else
tries and discovers that the thing doesn't compile in his specific
environment (usually with his favourite C compiler instead of gcc).
If you want to say that this is a flawed method for building software,
Click to expand...

Not flawed, merely suboptimal...

Dan
 

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